The present invention pertains to ejector discharge mechanisms within rotary sterilizers and coolers used to process canned products, such as canned fruits and vegetables. More particularly, the present invention pertains to a safety device that provides an automatic shutdown signal to the rotary sterilizer or cooler when cans are not properly discharging from the sterilizer or cooler.
A common device and method for discharging cans from an atmospheric rotary sterilizer is a star wheel that includes pairs of spaced-apart teeth that, when rotated, engage both chimes of a can to eject the can from the sterilizer. Ejected cans roll onto a discharge chute where sensors are positioned to monitor the cans as they roll out of the sterilizer. If the cans back up on the discharge chute, the sensors provide a signal to alert an operator or provide for automatic equipment shutdown.
However, it is not uncommon for cans to become damaged or deformed during processing and, as a result, not properly move within the spiral rail of a rotary sterilizer. For example, a damaged can may become lodged, as it revolves around the rotary sterilizer shell, between the upper edge of the spiral rail and the interior wall of the shell. When the teeth of the star wheel move around to engage the can and push it out of the sterilizer, the teeth miss the chimes, and may do further damage to the can. Either way, the can is not pushed out of the sterilizer and continues to revolve with the reel until it gets squashed at the end of the shell, which causes a major shutdown situation. An operator needs to stop the sterilizer, reverse the reel and reach into the shell to manually remove the damaged can.
Briefly described, the rotary sterilizer of the present invention includes a safety apparatus for monitoring proper discharge of cans from a rotary sterilizer having a rotary reel, a plurality of reel angles at the periphery of the rotary reel for moving the cans around a revolving path within the sterilizer, a spiral rail for guiding the cans from one end of the sterilizer to the other end along a spiral path, a discharge chute for receiving discharged cans from the sterilizer, and an ejector for discharging the cans onto the discharge chute. The safety apparatus includes a sensor positioned to detect the presence of a can that does not properly discharge from the sterilizer.
According to an aspect of the invention, the safety apparatus comprises a discharge chute extension that projects into the revolving path of the cans and is movable in reaction to engagement with a can that is not discharged by the ejector. Movement of the discharge chute extension provides an indication that a can has not properly discharged from the sterilizer and therefor needs to be manually retrieved from within the sterilizer.
According to an aspect of the invention, the discharge chute extension is positioned in the revolving path of the cans at a point for engagement with cans not properly discharged onto the discharge chute. Preferably, the discharge chute extension is movable at least partially in the direction of movement of a revolving can.
According to another aspect of the invention, the discharge chute extension forms part of the discharge chute. In this embodiment, the discharge chute extension is movable out of the revolving path of the cans upon engagement with a can not properly discharged.
According to another aspect of the invention, the discharge chute extension is movable along a linear path that is provided by a guide mechanism that limits movement of the discharge chute extension along the linear path. Preferably, the discharge chute extension includes a limit device for limiting the length of movement of the discharge chute extension.
According to another aspect of the invention, the discharge chute extension includes a sensor for detecting movement of the discharge chute extension.
According to another aspect of the invention, the discharge chute extension includes a spring bias against which a non-discharged can must work to move the extension. Preferably, the spring bias is adjustable to accommodate different size cans.
These and other features, objects, and advantages of the present invention will become apparent from the following description of the best mode for carrying out the invention, when read in conjunction with the accompanying drawings, and the claims, which are all incorporated herein as part of the disclosure of the invention.